I am in similar situation. There are few things that A99 has and A900 lacks that I think would be useful for me, live view is an example. However there are other things that I am undecided about or downright suspicious, like EVF, fixed mirror or better handling of high ISO noise. And there is bunch that I do not give 2 cents about, including video. I decided that buying new A99 and paying current price for it would be insane. Maybe in a year or two when early adopters move to something different I will pick up almost new body for peanuts but not now.

I could buy cheap low mileage A900 as a backup but here kicks in the doubt about full Alpha line future. Same applies for buying lenses. When brand has stability it is easier to quench our desire to foolishly spend money on that hobby as playing with some exotic lenses is usually not the cause of substantial loss. The perceived insecurity of Alpha line made me forget trying out Minolta 100 or Zeiss 135 and 24 and throw my money into some great Leica R which I can keep with me wherever I will go in the future. I will probably start rationalizing current Minolta lens collection leaving only bare necessities.